Most bomb related risks can be classified into one of five categories on the basis of the method of delivery, size of the device, and type of target:

1. Courier Delivered Explosive Devices

2. Mail Bombs

3. Anti-Vehicle Explosive Attacks

4. Proximity Bombs/Conventional Weapons of Mass Destruction

5. Projected Charge Attacks

Courier Delivered Bombs

In this type of attack, someone physically carries an explosive device into a target facility or into proximity of a target individual. This is accomplished through one of four methods for accessing the target: covert, overt, deceptive, or naive delivery. In most cases, the device is concealed at the target location and detonated after the bomber has escaped the area. In other situations, the bomber may detonate the device as soon as the target has been accessed (willfully sacrificing himself in the detonation).Specific characteristics of courier-delivered device attacks are detailed in Lesson Four of the Bomb Countermeasures for Security Professionals CD-ROM.

Mail Bombs

In this type of attack, the postal service is used to transport the IED to its target. In most cases, the device is concealed inside a letter, a package, or a second enclosure. In most mail bombings, the device uses anti-disturbance techniques to activate the device upon opening. Though their use is not very common, mail bombs are particularly malicious devices and should be carefully considered when evaluating bomb-related risk.Specific characteristics of mail bomb attacks are detailed in Lesson Six of the Bomb Countermeasures for Security Professionals CD-ROM.

Anti-Vehicle Explosive Attacks

There are four different types of explosive attacks directed against vehicles and their target occupants:

Proximity bombs, also referred to as Conventional Weapons of Mass Destruction (CWMD), are large scale explosive devices capable of creating damage and casualties over an extended distance, penetrating common types of structural barriers, and complicating rescue efforts with a high volume of casualties and post-blast hazards.

There are two principal types of CWMDs: Vehicle Bombs and Installation Devices. Vehicle bombs are typically constructed at one location and transported by vehicle to the target location. Vehicles are usually land-based or waterborne. Delivery is accomplished by deception, covert emplacement, proxy/or naive delivery, or overt penetration of perimeter defenses. The second type of CWMD, Installation Devices, are constructed at a static location close to the target and subsequently detonated.

In this type of attack, the perpetrator launches a conventional or improvised projected charge at a target vehicle or facility. Projected charges can be self-propelled or may thrown by hand. Common examples of projected charges employed by terrorists and criminals include: